https://bugzilla.redhat.com/show_bug.cgi?id=1389683
--- Comment #21 from Akira TAGOH tagoh@redhat.com --- Well, the basic workflow to use fontconfig is, 1) set the query to FcPattern to get better fonts according to it, 2) and collect with FcConfigSubstitute() and FcDefaultSubstitute(), at this time, FcPattern will be modified/filled out other properties according to the font configurations in /etc/fonts/conf.d and $HOME/.config/fontconfig/conf.d. 3) then FcFontMatch() and FcFontSort().
target="pattern" rules will be applied at 2) and target="font" will be applied at 3). apparently GNOME doesn't add their own hintstyle in dconf at 2) stage.